A mid turbine frame (MTF) system of a gas turbine engine sometimes referred to as an “inter-turbine frame”, is located generally between a high pressure turbine stage and a low pressure turbine stage of a gas turbine engine, to support one or more bearings and to transfer bearing loads therethrough to an outer engine case, and also to form an inter-turbine duct (ITD) for directing hot gas flow to the downstream rotor. It is conventional to have an oil transfer tube to radially pass the ITD in order to deliver oil to or discharge oil from the bearings. Oil leakage may occur from a seal located between the oil transfer tube and an oil port of a bearing housing. The leaked oil may enter into a high pressure turbine and/or low pressure turbine disk hub cavities and possibly ignite due to the high temperature environment in the cavities.
Accordingly, there is a need to solve this problem.